The invention relates to a medical lighting unit for clinical use comprising a lighting unit body containing at least one lamp and having at least one light outlet side, the lighting body unit being vertically adjustably mounted on at least one flexible and coilable tensile carrying element on a wall of a room, in particular on the ceiling of a room. The carrying element is secured at one end to the lighting unit body and at the other end to a drive unit secured to the room wall. The drive unit contains a drive motor for extending and retracting the tensile carrying element and extending vertically between the drive unit and the lighting unit body.
For operations in medical facilities such as clinics, hospitals or the like, lighting units with a particularly high light intensity of more than 70000 to 100000 Lux are required for the illumination of the position where the operation is to be carried out because human tissue, especially bloody tissue, absorbs a large part of the light. As a result, lighting units are known in operating theaters which are, as a rule, fixedly installed above the operating table and are movable, rotatable and liftable/lowerable by means of pivotal arms or spring arms.
For investigations on patients there are smaller examination lighting units in which the technical lighting requirements such as the intensity of the illumination, the color temperature or the like do not have to satisfy the stringent requirements of the operating theater lamp.
A special application for such lighting units are problematic births in gynecological clinics. In this arrangement the patients are frequently transported out of the actual delivery room, previously termed a labor ward, into an operating theater. This movement is not opportune for two reasons. On the one hand, an increased risk for the patient exists, especially in risky situations as a result of the transport and of the time which is lost. On the other hand, the patients increasingly wish to be able to give birth not in a labor ward, but rather in a separate individual room. This room should be cozily designed, since a normal birth is not a case of a surgical operation. Through the accommodation in individual rooms, the distances to the operating theater are, however, even larger in the case of an emergency.
Thus, there are already installations in individual patient rooms which permit smaller emergency operations such as cuts, sutures and other manipulations of a surgical nature. This additional technical equipment should not be visible in the normal case and should above all not hinder the mobility of people within the room. Since good lighting is required for such actions, of a similar quality to that of the operating theater, lighting installations are known which can, for example, transmit intense light rays to the patient""s bed, for example from the ceiling region or from the wall. However, such installations have the disadvantage that they are mainly rigidly arranged and secondly much light is lost through the large distance, for example between the ceiling and the patient""s bed.
A lighting unit is known in the non-medical field of application (EP0757204 B1) which can be lowered from the ceiling or lifted up to the ceiling, again by means of a motor and cables. This apparatus is, however, not particularly suitable for the medical application discussed, because two spaced-apart support wires are required between the drive unit and the lighting unit, which greatly impair the accessibility of the space above the lighting unit. A further disadvantage of the known lighting unit lies in the fact that it can only radiate light downwardly and cannot be adjusted other than in an upward and downward movement.
The object of the present invention is, on the one hand, to provide a medical lighting unit of the initially named kind which can be moved with a motor in a simple manner from a parking position close to the ceiling into a lower working position, without too much space being required above the lighting unit body for the tensile carrying element. The lighting unit should have operating theater light qualities, i.e. high luminous intensities and a color temperature close to that of daylight. Furthermore, the lighting unit body should be adjustable in a manner which is as universal as possible in all vertical settings other than the parking position, in order to be able to set an ideal luminating position, not only by suitable vertical adjustment, but rather also by tilting of the lighting unit body.
In order to satisfy this object the carrying element is realized as a single chain with measures or means being provided in order to set the lighting unit body in a desired illuminating position despite the single chain suspension.
The concept underlying the invention is thus to be seen in the fact that no longer a plurality of tensile carrying elements but rather, on the contrary, only a single chain is provided for the upwardly and downwardly movable support of the lighting unit body. A single chain requires considerably less space above the lighting unit body than a plurality of tensile carrying elements. However, measures must be taken, or means must be provided, in order to be able to set the desired lighting position of the lighting unit body. In accordance with the invention the lighting unit body has, in addition to the lamp, also an in built reflector, so that a high light intensity is ensured by light bundling.
In a preferred embodiment the chain acts laterally outside of the center of gravity of the lighting unit body on the latter, preferably at the outer edge of the lighting unit body on the latter, and consists of links which, with vertical alignment of the chain relative to the adjacent links, cannot be pivoted away from the lighting unit body.
This embodiment is particularly advantageous, since in this way the space above the lighting unit body is completely free from carrying elements and the single chain only extends upwardly to the drive unit from one side of the lighting unit body. As a result of the special design of the links of the chain, a situation is achieved in which the weight of the lighting unit body stiffens the chain so that it acts in a more or less downwardly extending state as a rigid bar. The chain is thus simultaneously a mounting element and a transport element which holds the lighting unit body in a defined position. Through the single chain, the lighting unit body can be moved by a motor between the parking position close to the ceiling and its working position.
In a particularly preferred embodiment the links can only be pivoted relative to the adjacent links in the direction towards the lighting unit body when the chain is vertically aligned.
Moreover, the neighboring links of the chain are pivotable relative to one another about only a single axis respectively pointing in the same direction, and indeed with a straight arrangement of the chain only in a direction deviating from the straight line direction, in which the lighting unit body is located.
These embodiments signify that the chain can be curved or bent only in a single plane, which leads to a particularly high stability of the vertically extending part of the chain.
In an advantageous further development of the invention an end piece to which the lighting unit body is attached at the side is secured to the lower end of the chain. This medical lighting unit is preferably characterized in that an at least substantially horizontal holding stub of the lighting unit body is secured to the lowermost link of the chain or to the end piece at the side. In this way the lighting unit body can be reliably secured to the lower end of the chain.
The lighting unit body is preferably movably secured to the chain, or to the end piece by a cardan joint. In particular a cardan hoop is preferably arranged between the lighting unit body and the holding stub. These embodiments ensure a universal adjustability of the lighting unit body secured to the lower end of the chain. In conjunction with the vertical adjustment the most diverse lighting positions of the lighting unit body can thus be realized.
The cable for the power supply of the lamp is arranged on or in the chain. I.e. the chain can simultaneously be used for the power supply to the lamp of the lighting unit body.
The lighting unit body is preferably accommodated in its highest position in a recess of the drive unit. In this way the light is not particularly apparent in the parked state and acts in similar manner to a normal ceiling lamp.
A preferred operating measure for the medical lighting unit of the invention is characterized in that an operating keyboard and an electronic control system for the introduction of an upward or downward movement of the lighting unit body are provided. In this arrangement a brief key actuation at the operating keyboard is sufficient, in a position between the highest position or parking position of the lighting unit body and a position in the lower range of movement of the latter, for example at two-thirds of the total range of movement from above, in order to displace the lighting unit body over this path.
A slow and in particular small step-wise upward and downward movement of the lighting unit body can preferably be initiated by key actuation in a range of movement (working range) lying in the vicinity of the lowermost position of the vertical adjustment.
The upward movement of the lighting unit body into the parking position by key actuation is blocked until the lighting unit body has been brought into the basic position, in particular a horizontal basic position, which it at least substantially adopts in the parking position.
An arrangement in which the chain extends vertically above the lowermost link over at least a few links in the parking position of the lighting unit body before a deflection takes place is particularly preferred, since in this way an adequate length of vertical chain is preferably provided within the drive unit. This ensures, as a result of the vertical guidance, that the vertical part of the chain projecting downwardly out of the drive unit is not pivoted by the eccentrically acting weight of the lighting unit body out of the vertical position. The uppermost part of the vertical range of the chain should preferably consist of at least a few links, preferably three to 10 links, and in particular four to six links and especially expediently five links, and is so vertically guided, preferably inside the drive unit, that an otherwise possible pivoting away movement of the lighting unit body about an axis in the region of the upper deflection of the chain within the drive unit is avoided.
A precondition for the action of the vertical part of the chain as a rigid bar is thus that the uppermost part of the chain is precisely vertically guided inside the drive unit against deflection as a result of the weight of the lighting unit body. In a particularly preferred embodiment the drive unit is accommodated between the room ceiling and a false ceiling arranged at a distance beneath it and the false ceiling has an opening for the emergence through it of the lower surface of the drive unit, such that the vertically upwardly moved lighting unit body appears to be integrated into the false ceiling.
One embodiment of the present invention permits the drive unit to be accommodated largely unseen, so that the upwardly moved lighting unit body appears to be integrated into the intermediate ceiling or false ceiling.